Power conversion machine with pistons rotating in pairs relative to each other in a spherical housing

ABSTRACT

The power conversion machine includes a housing which defines a spherical cavity as well as a stator which is secured within the housing on a first axis. The stator is provided with an annular groove which is disposed on an angle to the axis of the stator while an annular guide member is slidably mounted in the groove for rotation about the stator axis. A first rotor part is secured to a shaft which is rotatably mounted on the stator and carries a pair of pistons which define ball shaped segments within the cavity of the housing. A second rotor part having a second pair of pistons defining a pair of ball shaped segments within the cavity is disposed on a second axis perpendicular to the axis of rotation. Pins are used to secure the second rotor part to the annular guide member for rocking of the second rotor part about the second axis during rotation of the two rotor parts about the axis of rotation.

The present invention relates to a power conversion machine comprising afirst rotor part with a first pair of pistons and a second rotor partwith a second pair of pistons adapted to be moved in a spherical cavityin the machine housing, the second pair of pistons being positivelymovable in a rocking movement back and forth in relation to the firstpair of pistons, the first rotor part being connected to a driving ordriven rotary shaft, while the second rotor part is non-rotatablyconnected to the first rotor part so as to perform a conjoint movementof rotation about the axis of rotation of the rotary shaft, the firstrotor part being rotatable in a first path of revolution in a plane atright angles to the axis of rotation, while the second rotor part isrotatable together with and rockable in relation to the first rotorpart, and the second rotor part being guided by a guide member rotatablein a second path of revolution inclined by means of stationary guidemeans at an angle v in relation to the first path of revolution.

The present power conversion machine may be used in various fields, e.g.as a single-stage or multistage compressor, pump, hydraulic or pneumaticengine and, respectively, as a two-stroke or four-stroke internalcombustion engine etc. The machine can be employed for a large spectrumof various speeds. The machine is particularly useful as a high-speedmachine, such as a high-speed compressor or high-speed engine. When themachine is in the form of a pneumatic motor, steam engine or internalcombustion engine and has a moderate working volume, a speed of 500r.p.s. (30,000 r.p.m.) can be used. When the machine is an internalcombustion engine, a speed of about 100 r.p.s. (6,000 r.p.m.) can besuitable. In other cases, a speed of 50 r.p.s. can be more relevant forspecial other applications. In connection with propelling engines (e.g.diesel engines) for vessels, significantly lower speeds can beconvenient in consideration of the speed of the propellers, and speedsof 100 r.p.m. for the propeller(s) can then be relevant also to thepropelling engine. A special object is to provide a machine whicheffectively balances the moving masses in the machine, which results inminimal vibrations in the machine when operating. A further object is toprovide a machine of a comparatively compact design with relatively fewand simple parts and relatively small volume and weight in relation toits output. A still further object is to provide a machine whose workingchambers are sealed from the parts of the machine which are lubricated.A further object is to provide a machine in which simple and effectiveguiding of the various ports in the machine housing is achieved.

U.S. Pat. No. 826,985 (D. Appel) which was granted in 1906 gives asolution of the type mentioned by way of introduction, which yields afavourable movement of the pistons and the associated working chambersrelative to the various ports, based on a simple design with nocrankshaft and no separately moving valves.

The prior art solution suggests the provision of a stationary guidemeans which is positioned radially outside the working chambers of themachine, for positively guiding the second pair of pistons in a rockingmovement in relation to the first pair of pistons. There is disclosed anannular guide member which is guided in the stationary guide means in aguiding groove which is formed in the actual machine housing and whichmoreover extends radially beyond the actual machine housing.

According to the prior art solution, the first pair of pistons perform,in practice, a movement of rotation only, while the second pair ofpistons perform a corresponding movement of rotation and, besides, anadditional, positively guided rocking movement back and forth inrelation to the first pair of pistons. By means of said radially outerguide means, the second pair of pistons are positively guided in aspecial path of movement in a stationary plane in the spherical housing,i.e. with an annular guide means inclined in a path of revolution atsaid angle v in relation to the path of revolution of the first pair ofpistons. The rocking movement of the second pair of pistons back andforth in relation to the first pair of pistons occurs as a positivelyguided movement about a rocking axis extending transversely of the axisof rotation of the rotary shaft of the rotor assembly. This means thatall points on the piston surfaces of the second pair of pistons arecontinuously rotated about the axis of rotation of the rotary shaft, atthe same time as these points also perform a rocking movement back andforth in relation to the piston surfaces of the first pair of pistons.The combined movement of rotation and rocking movement of the secondpair of pistons produce a favourable movement pattern for the secondpistons (the second rotor part) in relation to the first pair of pistons(the first rotor part) and in relation to the enclosing machine housingwith spherical inner surfaces, without the second pistons runningthrough a dead center in the extreme positions of the rocking movement.

The result of the above-mentioned design is that the four differentchambers which are defined between the four pistons, are caused to movein a corresponding movement of rotation about the axis of rotation ofthe rotary shaft and are pairwise connected to the stationary ports inthe machine housing in fixed local areas of the paths of movement of thepistons and thus of the working chambers. In each of the cycles ofrotation of the rotary shaft, two of the working chambers are subjectedto an angularly uniform cubic expansion towards to a maximum, and thencontinuously undergo a corresponding, angularly uniform cubic reductiontowards a minimum in a subsequent stroke, while the other two workingchambers are correspondingly subjected to an angularly uniform cubicreduction towards a minimum and then continuously undergo an angularlyuniform cubic expansion towards a maximum in a subsequent stroke. Onepair of working chambers cooperate with a first pair of ports, while thesecond pair of working chambers cooperate with a second pair of ports.Consequently, a particularly uniform filling and uniform emptying of theworking chambers are provided in a first and a second pair of workingchambers in each stroke, and a change of stroke occurs immediately afterthe rockable pistons have reached their respective extreme position. Thechange of stroke does not occur via a marked movement of masses to thedead center between two pistons moving towards and away from oneanother, but with an even movement of masses via a positively guidedmovement of rotation of the pistons in relation to each other, inseparate paths of movement. This movement pattern is important, as willbe described below.

It is not previously known that the suggested, lastmentioned solutionhas proved practically useful - despite the favourable movement patternand the favourable operating conditions to which the rotor parts arecapable of being subjected. It is assumed that this is due to specialproblems which arise in connection with the positioning of the guidemeans radially outside the machine working chambers, in that the guidemember (guide ring) is subjected to especially high circumferentialspeeds and opens to the machine working chambers, which results inoperational drawbacks. It thus is a considerable drawback that therockable pistons in each of their rocking movements must movetransversely of the gap in the machine housing where the guide member(the guide ring) is mounted in the machine housing. There are greatproblems on the one hand of ensuring lubrication of the guide member inrelation to the machine housing and, on the other hand, of establishinga seal of the guide member above the working medium in the workingchambers of the machine. These problems are especially obvious inhigh-speed machines, particularly in high-speed internal combustionengines. It is assumed that these problems have been such that for thepast 80-83 years, no solution has been found, until the presentinvention was made.

U.S. Pat. No. 4,938,025 and corresponding Norwegian Patent Application882,801 discloses a power conversion machine of a similar, yetsubstantially different design, which eliminates some of the drawbacksof the above-mentioned prior art design, but which does not achieve allthe above-mentioned objects according to the invention. In the form of apump or compressor, the prior art solution functions efficiently,whereas in the form of an internal combustion engine it is morecomplicated, since a rotary crankshaft is used for moving all thepistons in a combined rocking and pivoting movement and since the valvesmust be specially operated in addition to the operation of the valveswhich is mounted in the machine housing.

According to the present invention, the problems of the two prior artsolutions are solved, and a solution is provided which has considerableadvantages as compared to the prior art solutions.

The machine according to the invention is characterised in that thefirst and the second rotor part are defined inwardly of a commonspherical generatrix corresponding to a spherical inner side surface inthe machine housing, and that a stationary guide means, for guiding thesecond rotor part in the rocking movement back and forth, is arrangedcentrally within the rotor assembly as an elongate stator, one end ofwhich is rigidly connected to the machine housing.

By subjecting the two pairs of pistons to a continuous movement ofrotation, while guiding the rocking movement back and forth of thesecond rotor part from the inner side of the rotor assembly and whileproviding for an effective seal of the stationary guide means and theguide member on the inner side of the rotor assembly, the pistons whichare arranged on the outer side of the rotor assembly, can be moved atcomparatively high speeds of motion, independently of outer guide meansetc. The chosen stationary guide means which is arranged internally, andthe associated, internally mounted guide member render a compact androbust design of the guide mechanism possible, which again makes itpossible to move the guide member at relatively low circumferentialspeeds, while the radially largest circumferential portion of the rotorassembly can move at substantially higher circumferential speeds,without causing any particular problems. Besides, the guide member andthe adjacent parts of the second rotor part can be balanced in acontrolled manner within the rotor assembly, without causing anyparticular vibration in the rotor assembly or the machine as such. Atthe same time the working chambers can be readily sealed from thelubricant areas for the guide means and the corresponding parts insidethe rotor assembly, with no risk of mixing the lubricants and the mediumwhich is processed in the working chambers of the machine.

According to the invention, an effective solution is readily achieved,especially for a high speed machine as stated by way of introduction, bydefining, as mentioned above, the rotor parts inwardly of a sphericalgeneratrix corresponding to a spherical inner side surface in themachine housing and by moving the stationary guide means from a radiallyouter position to a centrally inner position. This brings theconsiderable advantage that the ports can be formed in optionalpositions inside in the spherical surface of the machine housing,independently of the position of the guide means. A special advantage isthat the outside of the rotor assembly and the inside of the motorhousing can both be designed with spherical surfaces which can beadapted exactly to each other for rotation of the rotor assembly atparticularly high speeds of rotation. In this context, it is of greatimportance that the stationary guide means and the guide member arearranged radially inside the rotor assembly.

Provision is made for the guide means to be arranged coaxially with therotary shaft and extending through the machine housing from a bearingconnected with the inner end of the rotary shaft, to a stationarymounting in the opposite end of the machine housing.

As a result, the rotor assembly is effectively mounted on the stationaryguide means, at the same time as the guide member (guide ring) of thesecond rotor part can be effectively guided on the stationary guidemeans which is defined within the rotor assembly.

The stationary guide means extends centrally through the first rotorpart, in that the first rotor part is rotatably mounted relative to theguide means at the opposite ends thereof. Thus, also the rotor assemblycan be readily mounted in the machine housing.

As mentioned above, the present invention aims at avoiding anycommunication whatsoever between the lubricants (which are to lubricateespecially the bearing surfaces between the guide member and thestationary guide means, the bearing surfaces between the first rotorpart and the stationary guide means, and the bearing surfaces betweenthe second rotor part and the guide member) and the working medium(which is processed in the working chambers of the machine).

According to the invention, it is possible to ensure an effective,common seal of the internal bearing means of the rotor assembly and thebearing means of the internally arranged guide member, such that theycan be lubricated by means of a common lubricant system arranged in theform of channels in the stator of the machine. Therefore, the inventivemachine is characterised in that the first rotor part is passed endwisethrough the second rotor part through an annular, radially outer rotorpart portion, in that the first and the second rotor part jointly definea cavity which contains lubricants and is sealed against the workingchambers, said cavity enclosing the stationary guide means and theassociated guide member as well as the connecting means of the guidemember, which connects with the second rotor part.

The various solutions according to the invention (in the same manner asaccording to U.S. Pat. No. 826,985) do not generally necessitatevalve-operated ports, since the movements of the pistons can operate theopening (uncovering) and the closing (covering) of the ports merely bymeans of their movement of rotation relative to the ports in thespherical housing. The point of time for opening (uncovering) andclosing (covering) of the ports can be regulated by a correspondingoptional design of and corresponding positioning of the ports in thespherical housing, independently of outer stationary guide means andouter guide member. Use can be made of two intake ports and two exhaustports, i.e. one intake port and one exhaust port which are common to afirst pair of working chambers, while a further intake port and afurther exhaust port are common to a second pair of working chambers.

A practically favourable solution which in constructional respect issimple, implies that the first and the second pair of pistons, togetherwith the rotary shaft, constitute a rotor assembly, while the sphericalhousing and a guide means attached thereto, for guiding the second pairof pistons in the second guide path, constitute a stator assembly.

Use can here be made of but a small number of separate parts both in therotor assembly and in the stator, at the same time as a simple andrelatively compact constructional solution is provided, with low weightand comparatively small volume but with a relatively high output. Moreprecisely, the stator comprises the guide means and the machine housingwhich are rigidly connected to each other, while the rotor assemblycomprises the first rotor part, the second rotor part and connectingmeans attached thereto and hingedly connected to the guide member by apair of pivot pins, said guide member being rotatably mounted on thestationary guide means. In consideration of assembly and production, theparts are, in practice, divided into a large number of parts, butroughly seen the stator consists of a single part, whereas the rotorassembly comprises three cooperating parts (the two rotor parts and theguide member). In addition, the various parts can be readilymanufactured and mounted in a relatively simple manner, as will appearfrom the description below.

In a preferred solution according to the invention, the machine housingis, at each of its opposing ends, provided with a pair of ports which,in respect of the angle of rotation, are spaced apart and locatedinwardly of the paths of movement of the peripheral edges of thespherical outer surface of a respective end portion of the first rotorpart, said ports being adapted to be covered and uncovered by said endportions in the various positions or areas of rotation of the rotorassembly, in that the spherical outer surface which is defined on theend portions of the first rotor part and which is symmetrical relativeto the axis of rotation of the rotor assembly, is of a length which issignificantly larger than the width.

This means that according to the invention it is possible to guide theports in their entirety by means of the piston-forming end portions ofthe first rotor part.

According to the invention, it is possible, by using the machine as acompressor or pump or as a two-stroke internal combustion engine, toensure that two diametrically opposite working chambers are connected tomutually diametrically opposite ports constituting intake ports (and arethen connected to mutually adjoining ports constituting exhaust ports),while two other mutually diametrically opposite working chambers are atthe same time connected to the corresponding, mutually diametricallyopposite ports constituting exhaust ports in the respective fixed phasesof the respective strokes (and are then connected to mutually adjoiningports which constitute exhaust ports).

When the machine is in the form of a four-stroke internal combustionengine, the cavity of the motor housing defines, by means of the rotorassembly, four separate working chambers which separately and, in turn,pairwise are subjected to the respective two of the four strokes of theengine in communication with the respective two of the four ports, ofwhich at the same time a first port constitutes an air intake port to afirst working chamber, and a second port constitutes an exhaust port forcompressed air from a second working chamber to a connecting chamberarranged radially outside the working chambers, a third port constitutesan intake port from the connecting chamber to a third working chamberforming an expansion chamber, while a fourth port constitutes an exhaustport from a fourth working chamber to an exhaust outlet.

According to the invention, it can first be achieved that the connectingchamber connects one pair of working chambers operating on thesuction/compression side, to a second pair of working chambers operatingon the combustion/exhaust side of the machine housing. Secondly, it canbe achieved that the connecting chamber which preferably is arrangedoutside the cooling casing of the engine, can also constitute anexternal combustion chamber with nozzle(s) and igniting means.

By combining the external connecting chamber with an external combustionchamber, a number of considerable advantages can be obtained.

First, it is possible to simultaneously ensure that each of the fourstrokes (suction, compression, combustion and exhaust) occurs in one andthe same engine housing but each separately in one of the four workingchambers.

Secondly, it is possible to obtain a considerable simplification of theactual combustion process, a considerable simplification of the heatloss, a high combustion temperature and, as a consequence, a completecombustion of the fuel etc.

Therefore, the combustion chamber is preferably provided with a layer ofinternally heat-insulating, ceramic material.

This brings several considerable advantages.

First, the combustion in the combustion stroke of the engine can occuroutside the working chambers, such that the parts of the rotor assemblycan be held on a low thermal level, while the combustion chamber can beheld on a significantly higher thermal level, which can ensure effectivecombustion independently of the internal parts of the engine (the innerside of the machine housing, rotor assembly etc.).

More precisely, the combustion chamber can be attached in a stationarymanner to the engine housing itself, preferably outside both the enginehousing itself and the water casing of the engine, and independently ofthe engine rotor assembly, water casing, lubricant system etc.Correspondingly, the rotor assembly of the engine can be designed in amanner which is as favourable as possible in respect of rotation,independently of the actual combustion cycle and the design of thecombustion chamber.

Moreover, the working chambers with which the combustion chamber shallinteract, can be subjected to continuous rotation relative to the portwhich supplies the working medium from the stationary combustionchamber, such that also the kinetic energy of the hot gas flow in thedirection of movement of the working chambers can be efficientlyutilised.

A further essential advantage of attaching the combustion chamber in astationary manner outside the engine housing, is that one can obtaineffective combustion of the fuel at an especially high and at the sametime relatively even level of temperature, more or less independently ofthe temperature conditions inside the engine housing. The combustionchamber can readily be defined inwardly of an area which iscomparatively easily heat insulated and easily made resistant to hightemperatures (for example by lining the inner walls and, optionally, theouter walls with ceramic materials), such that the combustion chambercan be kept at a high constant level of temperature, thereby to ensurean effective, more or less complete combustion of the fuel. This resultsin both environmental advantages and a higher output of the engine. Inother words, the supply of heat locally to the external combustionchamber of the engine housing can be limited, and the supply of heat canto a large extent be restricted to this local area of the engine. Forthe same reason, a slightly lower level of temperature cancorrespondingly be obtained inside the engine housing, such that therotary parts of the engine can be kept at relatively low levels oftemperature which are easily controllable in a corresponding manner, byusing ordinary external water or air cooling of the engine housing andordinary internal oil cooling of the rotor assembly and its stationaryguide means and the associated guide member.

A further advantage is that the hot fuel gas can be supplied at highpressure directly to the different working chambers via a single portwhose opening area is accurately defined and for which the time foropening and closing is precisely set in relation to the cycle ofrotation. In practice, the flow of hot compressed gas can beapproximately fully continuous in a rapidly pulsating gas flow from thecombustion chamber to the immediately following working chambers,without ordinary valve operation and exclusively controlled by themovements of rotation of the rotor assembly.

By avoiding valve operation, cam shafts etc., one obtains considerableadvantages. For example, it is possible to easily use large ports fortaking in air and, respectively, letting out exhaust gas, thereby toensure that air is taken in correspondingly quickly and relativelyfreely and that exhaust gas is blown out quickly, with no need foradditional, moving parts, which is particularly favourable in high-speedengines. Accordingly, one can easily design the various ports with across-sectional shape and area which are fully determined by theintended way of flowing of the gas medium in the different strokes inthe engine housing and in the combustion chamber, respectively.

Further features of the present invention will appear from thedescription below with reference to the accompanying drawings in which:

FIG. 1 is a plan view of a power conversion machine according to theinvention, illustrated in a first embodiment in the form of acompressor,

FIG. 2 is a vertical cross-section of the machine in FIG. 1,

FIG. 3 is a perspective view of a first rotor part,

FIG. 4 is a perspective view of a second rotor part,

FIG. 4a is a side view of the rotor part in FIG. 3 and the rotor part inFIG. 4 in engagement with each other, portions of the second rotor partin FIG. 4 being shown in cross-section,

FIG. 5 is a vertical cross-section of the parts constituting the statorof the machine,

FIGS. 6-8 illustrate the rotor assembly of the machine in threedifferent operating positions,

FIGS. 9-10 illustrate the first and the second rotor part received inone housing section and shown in two different operating positions at anangular displacement of 90°,

FIG. 11 is a perspective view of the inventive machine in the form of afour-stroke internal combustion engine, an intake port and an exhaustport being especially shown,

FIG. 12 is the same view as in FIG. 11, shown from the opposite side andwith certain parts broken away for better clarity, the engine and theexternal combustion chamber being especially shown,

FIG. 13 is a cross-sectional view of the engine in FIGS. 11 and 12,

FIG. 14 is a perspective view of the guide means for a second rotorpart,

FIG. 14a is a cross-sectional view of the stationary guide means and theguide member of the second rotor part mounted in the associated guidegroove,

FIG. 15 is a side view, partly in section, of the guide means in FIG. 14and the associated guide member during mounting in connecting meanswhich connect the guide member to the second rotor part,

FIG. 16 is an exploded view of the assembly comprising the guide memberand the connecting means positioned between two halves which togetherconstitute the first rotor part,

FIG. 16a is a cross-sectional view of the first rotor part, with anangular displacement of 90° in relation to the view in FIG. 16,

FIG. 17 illustrates the first rotor part which comprises the halvesshown in FIG. 16, positioned between two portions which are included inthe second rotor part,

FIG. 18 illustrates the halves of the second rotor part, as shown inFIG. 17, in the assembled state,

FIG. 19 is a side view of the parts shown in FIG. 18 as seen from theright side in FIG. 18,

FIG. 20 is partly a side view and partly a longitudinal section of aportion of the second rotor part,

FIGS. 21 and 22 are end views of two halves which together constitutethe engine housing as shown in FIG. 13,

FIG. 23 is a longitudinal section of a structural member containing acombustion chamber outside the engine, and

FIG. 24 comprises schematic views of the first and the second rotor partin various angular positions relative to one another, thereby toillustrate the covering and uncovering of the ports in the variousstrokes in a four-stroke internal combustion engine as shown in FIGS.11-23.

As mentioned by way of introduction, the power conversion machineaccording to the invention can be used in a number of different fields,e.g. as a one-stage or multistage compressor, or as a pump, apneumatically or hydraulically operated engine, or as an internalcombustion engine or the like. The machine or the engine according tothe invention can be used in a number of different fields and in anumber of different combinations, without all such embodiments beingstated herein. Examples of a simple engine unit are given below, whilein practice a number of different possibilities of combination which canbring considerable advantages, are also feasible, for example whenarranging machines or engines in tandem connection or in interactingoperation in some other manner.

POWER CONVERSION MACHINE IN THE FORM OF A COMPRESSOR

In a first embodiment as illustrated in FIGS. 1-10, the power conversionmachine according to the invention will be described in an especiallysimple embodiment in the form of a compressor. The parts which aredescribed with reference to FIGS. 1-10 are, however, not limited to beused in a compressor, but can in principle just as well be used in othertypes of machines, without concrete examples thereof being mentionedbelow.

The machine according to the first embodiment generally comprises amachine housing 10, a rotor assembly having a first rotor part 19-21 anda second rotor part 33-35, a radially inner guide means 16 which isstationarily mounted in the machine housing and intended for a guidemember 38 which is rotatably mounted in a separate plane of rotation.The guide member 38 positively guides the second rotor part 33-35 in arocking movement back and forth relative to the first rotor part 19-21which exclusively performs a movement of rotation.

FIG. 1 shows a spherical machine housing 10 with a spherical innercavity. The housing is composed of two halves 11 and 12 and is dividedalong a transverse center plane or radial plane 10a which is indicatedby dash-dot lines in FIGS. 1, 2 and 5. The halves 11, 12 are each,provided with a mounting flange 13 and 14, respectively, which arejoined together by a number of mounting bolts 15a and mounting nuts 15b.There are shown two machine foundations 100a, 100b with mounting holes101 for mounting bolts (not shown).

The stator 10, 16 of the machine is shown in FIG. 5, while the rotorassembly 19-21, 33-35 of the machine is shown in FIGS. 6-8. The statorand the rotor assembly of the machine are shown in more detail in themounted state in FIGS. 2 and 4a. The first rotor part 19-21 and thesecond rotor part 33-35 are each shown separately in FIGS. 3 and 4.

To one half 11 of the machine housing, there is permanently attached asubstantially bar-shaped, stationary guide means 16 which extendsthrough the spherical cavity 10b in the spherical housing 10 (see FIG.2) transversely of the center plane 10a and extends a distance axiallybeyond the spherical cavity of the machine housing at the upper end ofthe machine housing as shown in the drawing. The guide means 16 has alongitudinal axis 16a which coincides with the axis of rotation 17a of arotary shaft 17. A thicker end 16b of the guide means 16 is rigidlyconnected with one half 11 of the housing, such that the guide means 16together with the halves 11 and 12 form a stator assembly.

In the upper part of the drawing (see FIG. 5), the guide means 16 isformed with a stem-shaped portion 16c followed by a ball-shapedintermediate portion 16d and a lower stem-shaped portion 16e merginginto the lower thicker portion 16b by which the guide means is connectedwith the half 11 of the housing.

In the other half 12 of the housing, the axially inner end 17b of therotary shaft 17 is rotatably mounted in a radially inner rotary bearing18. The axially opposite end 17c of the rotary shaft 17 extends endwisebeyond the housing 10 for engagement with a power-operated driving means(not shown) for rotating the rotary shaft 17 in, relation to the housing10 and the guide means 16.

The first rotor part 19-21 is rigidly connected to the inner end 17b ofthe rotary shaft 17. The rotor part comprises a first pair of pistons19, 20 which are rigidly interconnected by a common hub portion 21. Thefirst rotorforming part 19-21 is non-rotatably connected to the rotaryshaft 17. The rotor part 19-21 is rotatably mounted on external bearingsurfaces 22, 23, 24 adjacent the axially inner end 16b of the guidemeans 16 and on radially external bearing surfaces 25, 26 adjacent theaxially outer end 16c of the guide means 16. The outer end 16c of theguide means 16 projects endwise into the inner end 17b of the rotaryshaft 17, such that the inner end 17b, radially internally, is rotatablymounted on the outer end 16c of the guide means 16 and, radiallyexternally, is rotatably mounted in the rotary bearing 18 in the half 12of the housing.

As appears from FIG. 3, the pistons 19, 20 and the hub portion 21 aredivided into two halves 19a, 20a, 21a and 19b, 20b, 21b along apartition surface indicated by the parting line 27, such that the twohalves can be mounted about the guide means 16 from opposite sides,while this is attached to the half 11 of the housing, but before thehalf 12 of the housing is mounted on the half 11 of the housing.

The pistons 19, 20 have the shape of elongate ball segments. The hubportion 21 which is located centrally in the housing 10 has the shape oftwo axially spaced-apart, cylinder-shaped sleeves 21a and 21b with anintermediate gap 21c. The sleeves 21a, 21b extend over a length of about1/3 of the inner diameter of the housing 10. The sleeves define betweenthemselves an intermediate ball-shaped cavity 28 (see FIGS. 2 and 4a)which receives the ball-shaped intermediate portion 16d of the guidemeans 16 and an associated annular guide member 38. The guide member 38is provided with pins 39 extending radially outwards from the guidemeans 16 and from the ball-shaped cavity 28 via said gap 21c in therotor part 19-21.

At the opposite ends of the hub portion 21 there is formed a recess 31and 32, respectively (FIG. 3) with cylindrically curved surfaces 31a,31b and, respectively 32a, 32b.

To the first rotor part 19-21 there is attached separate second rotorpart 33-35 which is shown in more detail in FIG. 4. As appears fromFIGS. 2 and 4a, the rotor parts 19-21 and 31-35 constitute a rotorassembly. The rotor part 33-35 comprises two pistons 33, 34 and anintermediate hub portion 35. In conformity with the pistons 19, 20 andthe hub portion 21, the pistons 33, 34 and the hub portion 35 aredivided into two halves 33a, 34a, 35a and, respectively 33b, 34b, 35b bymeans of a partition plane which as shown in FIG. 4 is in the form of aparting line 37. The two hub portion halves 35a, 35b are, however,divided such that they form between themselves a cavity for receivingthe hub portion halves 21a, 21b of the first rotor part.

In mounting, the guide member (guide ring) 38 is first mounted on theguide means 16. Subsequently, the two halves of the first rotor part19-21 is mounted in the lower half 11 of the housing about the guidemeans 16 from opposite sides thereof and simultaneously in firm rotaryengagement with the rotary shaft 17. Then the second rotor part 33-35can be mounted on the first rotor part 19-21. In practice, one half 33a,34a, 35a of the second rotor part can be mounted on the correspondinghalf 19a, 20a, 21a of the first rotor part. Correspondingly, the otherhalf 33b, 34b, 35b of the second rotor part can be moved lengthwise intoengagement with the corresponding other half 19b, 20b, 21b of the firstrotor part.

The annular guide member 38 is divided into two sections 38a, 38b asshown in FIG. 4. The guide member 38 comprises two pins 39 which extendradially outwards and are made coherent with a respective one of the tworing halves 38a, 38b. The opposite end of the pins is rotatably mountedin a corresponding bore forming a rotary bearing in the respective twopiston parts 33, 34 of the second rotor part 33-35. The ring 38 isrotatably mounted in a groove 41 in the ball-shaped portion 16d of theguide means 16 and is, together therewith, mounted in the ball-shapedcavity 28 between the hub portion sleeves 21a and 21b of the first rotorpart, as shown in FIG. 4a. The central main plane of the ring groove 41,which is indicated by a dash-dot line 41a, in FIG. 5 makes an angle vwith the plane 10a extending at right angles to the center axis 16a ofthe guide means 16.

In the embodiment illustrated, the angle v is shown to be 30°, but inpractice it can be larger or smaller, as desired and required. When theangle v is chosen to be for example 30°, the second pair of pistons canbe moved through 60° in relation to the first pair of pistons in eachstroke. If the pistons are made thinner, one can, for example, use anangle of 45°, which results in an angular movement of 90° for each ofthe pistons in the second pair of pistons in relation to the first pairof pistons in each stroke. The pistons can have the shape of ballsegments or are in any case formed with spherical outer surfacescorresponding to the spherical inner side surface of the machinehousing.

As appears from FIG. 2, the rotor parts 19-21 and 33-35 constitute arotor assembly which is adapted to rotate about the axis 17a of therotary shaft 17 in relation to a stator assembly mounted in the housing10 and comprising the guide means 16.

The second rotor part 33-35 is positively rocked in a reciprocatingmotion in relation to the first rotor part 19-21 about a pivot axis 35c(see FIG. 4) which extends centrally through the hub portions 35a, 35bof the second rotor part 33-35 and intersects the axis 17a of the rotaryshaft 17 at right angles to the axis in the center of the cavity 10b.Pins extend through intermediate gap 21c between hub portion sleeves 21aand 21b of the first rotor part so as to be rotated by the first rotorpart. In consequence of the positive guiding of the ring 38 in the plane41a in the annular groove 41 in the stationary guide means 16, the guidering 38 is rotated in a separate path of revolution in relation to theguide means 16, i.e. it is rotated in the plane 41a which extendsobliquely to the plane of rotation of the first rotor part 19-21, whichextends at right angles to the axis of rotation 17a. The pins 39 of theguide ring 38 will perform a pivoting movement back and forth inrelation to the pistons 33, 34, and consequently the second rotor part33-35 will be put into a positive rocking movement back and forth aboutthe pivot axis 35c, at the same time as the first rotor part 19-21 (andthe second rotor part 33-35) makes a revolution about the axis ofrotation 17a of the rotary shaft 17.

THE WORKING CHAMBERS OF THE COMPRESSOR

As shown in FIGS. 2 and 6-10, two pairs working chambers 42, 43 and 44,45 are formed, i.e. one pair of working chambers on each side of thepistons 19 and 20 and, respectively, on each side of the pistons 33, 34.For better understanding of the mode of operation of the pistons, thepistons 19, 20 can be regarded as relatively static in relation to thepiston 33, 34. It appears that the rocking movement is only carried outby the pistons 33, 34, and these working chambers are expanded orcompressed as a consequence of the movement of the pistons 33, 34 inrelation to the pistons 19, 20. However, the pistons 19, 20 and thepistons 33, 34 will perform a synchronous rotation about the axis 17a ofthe rotary shaft 17, but with a movement of rotation in the radial planeat right angles to the axis 17a of the rotary shaft 17 in respect of thepistons 19, 20, and with a movement of rotation in the radial planewhich extends obliquely to the axis 17a, in respect of the pistons 33,34. The pistons 33, 34 rocking back and forth do not perform an ordinaryreverse movement in their extreme positions, but a movement of rotationwhich is continuous in space and has no dead centers.

As appears from FIG. 5, the housing 10 and the guide means 16 constitutea stator assembly. The first rotor part 19-21 is rotatably mounted onthe guide means 16 about the axis 17a, while the second rotor part 33-35is rockably mounted on the first rotor part 19-21 about the axis 35c andis rockably connected to the guide ring 38 which is rotatably mounted onthe guide means 16. The positive rocking movement which the second rotorpart 33-35 performs in relation to the first rotor part, is of courseguided by means of the inclined guiding groove 41 in the ball-shapedportion 16d of the guide means 16.

FIGS. 6-8 illustrate the pistons 19, 20 and 33, 34 in three differentphases of the rocking movement of the pistons 33, 34 in relation to thepistons 19, 20. In a first phase as shown in FIGS. 6 and 9, the workingchambers 42, 43 are shown in the lateral direction in FIG. 6 and fromabove in FIG. 9 and with their maximum volume, whereas the workingchambers 44, 45 are shown with their minimum volume. In a second,intermediate phase as shown in FIGS. 7 and 10, the pistons are forbetter clarity shown in a perspective view in FIG. 7 and from above inFIG. 10 and with correspondingly large working chambers 42-45. FIG. 8shows the pistons in a third phase in which the working chambers 44, 45have their maximum volume, whereas the working chambers 42, 43 havetheir minimum volume. When the rotor assembly is moved through half arevolution about the axis 17a, the pistons are subjected to theabove-mentioned three phases as shown in FIGS. 6-8 in a first stroke,and while the rotor assembly is further moved through half a revolutionabout the axis 17a, the pistons run through the corresponding threephases in the opposite order. It is thus obvious that each of the fourworking chambers 42-45, in a full revolution of the rotor assembly, issubjected to two successive strokes, and for each revolution of therotor assembly, four units of volume corresponding to the volumes of thefour working chambers are emptied and filled.

The filling and emptying of the working chambers 42-45 are effected viatwo pairs of intake ports 46 (only one indicated by dashed lines inFIGS. 9 and 10) and two exhaust ports 47 via associated pairs of exhaustpipes 48 and intake pipes 49 (FIG. 1). Use can of course be made of anintake port and an exhaust port in each of the halves 11 and 12 of thehousing and, of course, a common intake port and a common exhaust portfor each pair of working chambers which are positioned each on one sideof the pistons 19, 20. In FIGS. 9 and 10, there are indicatedquadrangular inner apertures 46a, 47a opening into the cavity 10b andcircular outer apertures 46b, 47b opening into the pipes 48, 49. In theembodiment shown, all ports 46 and 47 are adapted to open and close inthe extreme positions of the pistons as illustrated in FIGS. 6 and 8 andto be, as it were, fully uncovered in the intermediate positions shownin FIG. 7. In practice, it is however possible to dimension, form andposition the ports such that they are kept open in the entire stroke orjust in certain parts of each stroke, as required.

FIG. 2 shows sealing means 52 on the surfaces of the pistons 33, 34,which are directed radially inwards and face the hub portion 21 of therotor part 19-21, and sealing means 53 on the surfaces of the pistons33, 34, which are directed radially outwards and face the inner surfaceof the housing 10. Corresponding sealing means 50 are in FIG. 2 shown onthe surfaces of the pistons 19, 20, which face radially outwards. InFIG. 3, sealing rings 51 are indicated on the radial surfaces of the hubportion 21. An efficient seal between the rotor parts and between eachrotor part and the housing 10 can be established in a relatively simplemanner.

It is not here described but it will be possible to provide effectivelubricating and cooling of the rotor assembly by supplying a circulatinglubricating and cooling medium via the guide means 16 and the rotaryshaft 17, respectively, to each rotor part.

POWER CONVERSION MACHINE IN THE FORM OF AN INTERNAL COMBUSTION ENGINE

Below follows a description of an embodiment which is especially adaptedto use in an internal combustion engine, but the same design as isdescribed for the rotor in the internal combustion engine can also beused for the rotor in other types of machine, e.g. for a machine in theform of a pump, compressor or the like, without especially exemplifyingthis. The most essential difference is that the machine housing isadapted to the respective use, while the same motor assembly can be usedin all the different applications. In a rotor assembly for an internalcombustion engine, the rotor parts can of course be subjected to surfacetreatment or be specially made, such that they can be especiallyheat-resistant and heat-insulated, for example by means of ceramicmaterials, whereas such surface treatment or such special manufacture ofthe rotor parts is not absolutely necessary for other types of machine.

FIGS. 11-24 illustrate a second embodiment of the machine according tothe invention in the form of an internal combustion engine. Moreprecisely, there is shown a four-stroke double-acting internalcombustion engine having an external combustion chamber.

Alternatively, use can be made of a corresponding engine having aninternal combustion chamber, without a concrete embodiment thereof beingshown.

This also applies to other types of internal combustion engine. Even ifno concrete embodiments are shown, the internal combustion engine can beused as e.g. a two-stroke single-acting engine having external orinternal combustion chambers, without any examples thereof being given.

FIG. 13 shows an engine housing 110 which consists of two halves 111 and112 and which is divided along a transverse center plane 110a. Thehalves of the housing are each provided with a mounting flange 113 and114, respectively, which are joined by a number of mounting bolts 115.

The exterior of the engine housing 110 is provided with cooling fins105. The engine housing 110 is enclosed by a casing 106, thereby todefine two separate water chambers 107 between the engine housing 110and the casing 106, for circulating the cooling water in each waterchamber separately. The circulation of cooling water is in FIG. 12indicated by arrows 108, and the inlet of cooling water is indicated byarrow 108a and the outlet of cooling water is indicated by arrow 108b.The two parts 106a and 106b of the cooling water casing are attached byscrews 108c to the flanges 113 and 114 of the engine housing 110, and byscrews 108d to the opposite ends of the engine housing 110. At 109,there are shown mounting brackets for mounting the engine in horizontalposition to a base.

In FIG. 11, there is connected to an air inlet nozzle 161a a branchsuction line 166 which opens into a defined area 167 and 168,respectively (see FIG. 13) between the outer surface of the rotor part124, which has the smallest diameter and the inner surface of the halves111 and 112 of the engine housing, which has the smallest diameter. Thismakes its possible to remove, in per se known manner, via the air inlet,undesired gas residues from the cavity of the engine housing, withoutsuch residues having to come into contact with the lubrication systeminside the rotor assembly.

In FIG. 13, there are, at the end of the engine, which supports theguide means 116 constituting the stator, connected one supply pipe 169and two return pipes 170, 171 for lubricating oil which is distributedvia the stationary guide means 116 to the guiding groove 118 and to therotary parts which enclose the guide means 116 inside the rotor assembly124, 125.

FIG. 13 illustrates the most vital parts of the engine in the assembledstate. Some parts are removed for better clarity. These most vital partsare shown in more detail in FIGS. 14-23. Below reference will be madealternately to the general plan in FIG. 13 and the detailed plans inFIGS. 14-23.

THE GUIDE MEANS OF THE ROTOR ASSEMBLY

To the right end of the engine housing 110 in FIG. 13 there is attachedan elongate guide means 116 which extends through a spherical cavity110b in the engine housing 110, transversely of the center plane 110a.The guide means 116 has a longitudinal axis 116a (see also FIG. 14)which coincides with the axis of rotation 117a of a rotary shaft 117,i.e. the driven shaft of the engine. The guide means 116 is guidedendwise in a bore 117c in the right end 117b of the rotary shaft 117.There is shown a bearing guide 117c' in the bore 117c of the rotaryshaft 117 for support of the end portion 116c of the guide means 116 tothe left in FIG. 13. Said left end 116c of the guide means 116 isinserted in and enclosed by the lower end of the rotary shaft 117.

By means of a key groove 116d in the guide means 116 and a correspondingkey groove (not shown) in a terminal cover 112a mounted on the housingportion 112 by bolts 112d and corresponding keys (not shown), the guidemeans 116 is permanently attached to the housing portion 112.Consequently, the guide means 116 constitutes together with the enginehousing a stator assembly (see FIG. 14). A rotor 124, 125 is guided outof this stator assembly, said rotor being built up around the guidemeans 116 inside the spherical cavity 110b of the engine housing, aswill be described in detail below.

The guide means 116 as shown in FIG. 14 is formed with a lowerstem-shaped portion 116e which approximately in the middle of the lowerstem portion has a stop-forming, annular collar portion 116f. Moreover,the guide means is formed with a ball-shaped hub portion 116g having anannular groove 118, and an upper stem-shaped portion 116c. The groove118 is of dovetail-shaped cross-section and extends in a plane which isindicated by dash-dot lines 118a and which makes an angle v with theparting line 110a. In the groove 118 there is arranged a guide member inthe form of a guide ring 119. The guide ring 119 is divided into twosections along a plane through the axis 116b (FIG. 14a), thereby toallow mounting in the groove 118. In the illustrated embodiment theguide ring 119 is located between two separate bearing guides 119b and119c. The guide ring 119 is on two diametrically opposite sides providedwith bores 119a which form radially outwardly open pivot bearings andwhich are adapted to receive corresponding, radially inwardly extendingpins 120 which extend radially inwards from a connecting means 121constituting guide means (see FIGS. 16 and 20). The connecting means 121is included in the second rotor part 125, as will be described below.Said first rotor part 124, said second rotor part 125 and said guidering 119 are all incorporated in a common rotor assembly.

THE ROTOR ASSEMBLY CONNECTION WITH THE GUIDE MEANS

FIG. 15 illustrates the mounting of the guide means 116 and theassociated guide member or guide ring 119 in the connecting means 121.The connecting means 121 consists of two halves 121a, 121b of which onlyone half 121a is shown in FIG. 15, while the other half 121b is shown inFIGS. 13 and 16. The spherical hub portion 116g of the guide means 116is received in a correspondingly spherical recess (not shown) on theinside of the halves 121a, 121b, while two separate end pieces 123a and123b are inserted endwise from opposite sides of the connecting means121 and are connected to the respective two halves 121a, 121b thereof bymeans of mounting screws 122 (see FIG. 13) which are indicated bydash-dot lines to the right in FIG. 15. In FIG. 15 one end piece 123a ismounted in the connecting means 121, whereas the other end piece 123b isready to be moved in between the halves 121a, 121b (the half 121 b isnot shown in FIG. 15 for better clarity, but is assembled with the half121a in connection with the respective end piece 123a, 123b). The endpieces 123a, 123b are formed with a spherically curved inner surface asindicated by a dashed line 123d'. The end pieces 123a and 123b are eachprovided with a terminal pin 123a', 123b'.

As shown in FIG. 13, the terminal pins 123a', 123b' are rigidlyconnected to the rotor part 125 via spacer sleeves 126 and intermediatekeys as shown by means of a key groove 126'.

FIG. 16 shows the connecting means 121 mounted around the guide means116 and the guide ring 119 and locked relative to the hub portion of theguide means 116 by means of the end pieces 123a, 123b which are screwedto the two opposite portions 121a, 121b of the connecting means 121. Bymeans of recesses 121c, 121d in the connecting means 121, as shown inFIG. 16, the connecting means 121 is allowed to rock in a rockingmovement back and forth along a certain, limited arc about an axis 123'extending through the pins 123a' and 123b'. Since the connecting means121 forms connecting means between the guide ring 119 and the secondrotor part 125, the connecting means 121 is subjected to rotation aboutthe axis of rotation 117a in conformity with the rotor part 125 as such.As a result of the positive rotation of the guide ring 119 about an axis116b (FIGS. 13 and 14a) which extends at right angles to the plane 118a,the connecting means 121 performs, owing to the pin connections betweenthe connecting means 121 and the guide ring 119, an additional rockingmovement about the axis 123' in addition to the movement of rotationabout the axis 117a. This rocking movement is transferred via theterminal pins 123a, 123b of the connecting means 121 to the rotor part125. The rotor part 125 performs a corresponding positive rockingmovement in relation to the rotor part 124, as will be described indetail below, at the same time as the parts 121, 124, 125 perform aconjoint movement of rotation about the axis of rotation 117a.

THE FIRST ROTOR PART OF THE ROTOR ASSEMBLY

FIG. 16 is an exploded view and illustrates how the parts 116, 119 and121 are received in enclosed manner between two housing portions 124a,124b of the first rotor part 124.

FIG. 17 shows the housing portions 124a, 124b, assembled to a coherentrotor part 124 forming a housing. The rotor part 124 has a main axis124' which coincides with the axis of rotation 117a of the rotary shaft117, and the housing or rotor part 124 performs a movement identicalwith and along with that of the rotary shaft 117 of the engine.

The first rotor part, i.e. the housing 124, encloses, by means of anupper end sleeve portion 124d shown in FIG. 16, the lower end of therotary shaft 117 and is rigidly connected thereto via a mounting key124e (see FIG. 13), such that the housing 124 is non-rotatably connectedto the rotary shaft 117. There are shown a labyrinth seal 117e betweenthe half 111 of the engine housing and the rotary shaft 117, two sealingrings (radial packing rings) 117f, 117g and an intermediate bearing ring117h with a bearing guide 117h' between the rotary shaft 117 and abearing housing 110' and an associated end cover 110". Correspondingly,there are arranged an end cover 116i for retaining a sealing ring(radial packing ring) 124i at the sleeve-shaped end portion 124g of thehousing 124. In a first groove in the housing 124 there is arranged asealing ring (radial packing ring) 124i, and in a second groove thereare arranged two thrust bearings 124k each on one side of the annularcollar portion 116f (see FIGS. 12 and 13). At 124m there is shown abearing guide for supporting the guide means 116. Between the half 112of the housing and the end cover 116i in the terminal cover 112a of thehousing 110, there is shown a labyrinth seal 116h.

THE SECOND ROTOR PART OF THE ROTOR ASSEMBLY

FIG. 17 illustrates two end pieces 125a, 125b which jointly (andtogether with the connecting means 121) are to form a coherent rotorpart 125 and which from opposite sides are passed onto the housing 124.

As shown in the housing portion 124a in the upper part of FIG. 16 and inthe housing portion 124b in the lower part of FIG. 16, the second rotorpart 124 is provided with a sleeve-shaped hub portion 124t whose outsideguides the pistons 135, 136 of the second rotor part 125 and whoseinside guides the connecting means 121.

FIG. 18 illustrates the two end pieces 125a, 125b after being assembledso as to form the coherent rotor part 125 by means of common mountingscrews as shown by dash-dot lines 125c via overlapping finger-shapedportions 125d, 125e. The finger-shaped portions 125d, 125e extendendwise outwards in the axial direction on mutually opposite sides ofpart-spherical portions 125a', 125b'. The axially directed flangeportions 125a', 125b' extend between the finger-shaped portions 125d,125e. FIG. 19 illustrates the end piece 125a (corresponding to the endpiece 125b) as seen from one end. There are shown sealing rings 125a"'for sealing the end pieces 125a, 125b of the rotor assembly against thespherical inner wall of the engine housing (in the cavity 110b) andcorresponding sealing rings 129 (see also FIG. 13) for sealing thehousing 124 in relation to the spherical inner wall of the enginehousing.

To assemble the end pieces 125a, 125b such as shown in FIGS. 17-18, theopposing edge flanges 125a', 125b' of the end pieces 125a, 125b aremoved into corresponding recesses 124p and 124r in the connecting means121. In the edge flanges 125a', 125b' there are arranged incorresponding sealing grooves two separate sealing rings 129 as shown bythick black lines in FIG. 13. The sealing rings 129 extend coherently inthe longitudinal direction of the two opposing piston-forming portionsof the first rotor part 124 and annularly in the intermediate areatowards the edge flanges 125a', 125b'. FIG. 13 shows at 125a"', threesealing rings (see also FIG. 19) extending in parallel with each otherand along the entire circumference of the second rotor part 125. Thesealing rings 125a"' and 129 are designed with a largely T-shapedcross-section which is received in a correspondingly T-shaped groove,the cross-bar of the T shape being disposed at the bottom of the groove.In operation, the sealing ring is intended to be thrown by centripetalforce against the inner wall of the engine housing and there get worn,thereby to ensure effective sealing engagement without any considerablefriction between the parts. Inside the end pieces 125a, 125b (see FIG.13), the sleeve-shaped bearings 126 accommodate the key 126' such thatthe pins 123a, 123b of the connecting means 121 can, as mentioned above,be rigidly connected to the end pieces 125a, 125b. As mentioned above,there is provided by means of the keys 126' a coherent rigid connectionbetween the rotor parts 121, 125, such that they can perform a conjointmovement of rotation in relation to the rotor part 124. On the outsideof the sleeve-shaped pivot bearing 126 there are shown an annularprotective cover 127 between the housing portions 124a 124b and the endpieces 125a, 125b and axially inwards thereof, a rotary bearing 128 withan associated bearing guide 128' and a sealing ring (radial packingring) 128" arranged between the cover 127 and the rotary bearing 128and, respectively, between the respective and piece 125a, 125b and thehousing 124. FIG. 13 illustrates mounting bores 130 for assembling thehousing portions 124a and 124b.

By means of a comparatively simple sealing system, it is thus possibleto establish an efficient seal between the mutually movable rotor parts124, 125 (and, respectively, between the rotor parts 124, 125 and thespherical inner surface of the engine housing), such that the guidemeans 116 and the associated guide member (guide ring) 119 and theconnecting means 121 connected thereto are sealed radially inside therotor parts 124, 125 of the engine and the associated working chambers131-134, as will be described in detail below.

FIG. 18 shows the rotor parts 124, 125 from one side, and FIG. 19 showsthe rotor parts 124, 125 after they have been rotated through 90° aboutthe axis of rotation 117a. The rotor part 125 has two diametricallyopposite pistons 135, 136 with opposing piston surfaces 135a, 135b and,respectively, 136a, 136b. The pistons 135, 136 which are jointly movedabout the axis 135' (see FIG. 18) in relation to the housing 124, areformed of the projections 125d and 125e of the end pieces, saidprojections overlapping each other and forming fingers (FIG. 19 is anend view of the pistons 135, 136).

THE PISTONS OF THE ROTOR ASSEMBLY

The pistons 135, 136 are, as illustrated in FIG. 19, movable in arocking manner back and forth in relation to the rotor part 124 awayfrom and towards the opposite piston surfaces 137a, 137b of an upperpiston 137 and, respectively, the opposite piston surfaces 138a, 138b ofa lower piston 138. As shown in FIG. 19, working chambers 131-134 aredefined inwardly of the dashed lines indicating the inner wall of theengine housing. A first upper working chamber 131 and a first lowerworking chamber 132 are defined between the pistons 137, 138 and thepiston 135, while a second lower working chamber 133 and a second upperworking chamber 134 are defined between the pistons 137, 138 and thepiston 136.

During rotation of the rotary shaft 117, the rotor part 124 and therotor part 125 perform a conjoint movement of rotation about the axis117a.

Owing to the pin connection between the guide ring 119 of the guidemeans 116 and the connecting means 121, and the pin connection 123a,123b between the connecting means 121 and the rotor part 125, the rotorpart 125 performs, as a result of said rotation, a positive rockingmovement in relation to the stationary guide means 116 and in relationto the rotor part 124. More precisely, the guide ring 119 performs apositive movement of rotation in the associated guiding groove 118 inthe guide means 116 along the plane 118a (FIG. 14) and, at the same timeas the connecting means 121 is rotated about the axis 117a together withthe rotor part 125, the guide ring 119 positively causes a rockingmovement of the motor part 125 via the connecting means 121 about theaxis 123'. The pistons 135, 136 make a corresponding rocking movementback and forth between the pistons 137, 138 and alternately increase thevolumes of the working chambers 131, 133, while the volumes of theworking chambers 132, 134 are reduced, and vice versa.

For each revolution of the rotor part 124, 125 about the axis 117a, eachof the working chambers 131, 133 is filled and emptied once, while eachof the working chambers 132, 134 is correspondingly emptied and filledonce, i.e. each working chamber is subjected to a complete emptying andfilling cycle for each revolution. In working chambers:

1) suction stroke and 2) compression stroke, and for a second pair ofworking chambers:

3) combustion stroke and 4) exhaust stroke.

Each pair of working chambers 131, 132; 133, 134 are in turn eachsubjected to two subsequent strokes separately in a continuous cycle.

EXTERNAL CONNECTING CHAMBER/COMBUSTION CHAMBER

FIG. 12 illustrates an external connecting chamber, more precisely acombined connecting chamber and combustion chamber 150 which will bedescribed in more detail below with reference to FIG. 23. Even if,according to a preferred embodiment, the engine is here described inconnection with the external combustion chamber 150, the invention isnot limited to the use of such an external combustion chamber. It willalso be possible (even if it is not shown in detail) to effect thecombustion in the cavity 110b of the actual engine, i.e. in therespective working chamber in the cavity 110b of the engine, as theworking chambers take a corresponding position inside a determined rangeof angle of rotation in the cavity 110b. In the latter case, the chamber150 will only serve as an external connecting chamber and in that casethe chamber can be arranged as a duct in the actual engine housing. Byconnecting chamber is generally meant a connecting duct connecting onepair of working chambers with the other pair of working chambers, suchthat the two strokes in one pair of working chambers can continue in thenext two strokes in the other pair of working chambers.

It is also possible to provide a four-stroke internal combustion enginewithout said connecting chamber even though there is no illustrationherein of such an embodiment.

As appears from FIG. 23, the combustion chamber 150 is formed in aseparate structural element 150a which can be made as a separate unitconsisting of two halves 150a' and 150a" and which can be mountedseparately outside the engine housing and on the outside of the casing106 (not shown in FIG. 23). By means of connecting means 150d and 150eextending through the casing, and mounting screws 150d' and 150e', thestructural element 150a is mounted directly on the engine housing 110,the connection from the combustion chamber 150 to the ports 162 and 163being open.

In an alternative case where the combustion occurs within the actualcavity 110b, the structural element 150a constitutes connecting meansbetween two of the working chambers (compression chamber and combustionchamber, respectively). The two halves 150a', 150a" of the structuralelement 150a (see FIG. 12) are joined by mounting bolts 150b andattached to the engine housing 110 by the mounting bolts 150d' and150e'.

FIG. 23 is a cross-sectional view of the halves 150a', 150a", each ofwhich is coated (in a manner not shown) on the inside, (optionally alsoon the outside) with a heat-resistant and heat-insulating layer ofceramic material, such that the combustion chamber can be held at anoptimally high level of temperature, thereby to ensure optimalcombustion at a high level of temperature. At the same time, it ispossible to prevent removal of heat from the combustion chamber to thesurroundings and, respectively, to the cooling water in the casing.

In the outer part 150a" of the structural element 150a and approximatelyin the center of the part 150a", there is shown an insertion sleeve 150ffor an igniting means (iginition plug) 150f'. The use of an incandescenttube or similar ignition means (e.g. diesel or semi-diesel engine) isalso possible even though there is no specific illustration thereofherein. In opposite ends of the combustion chamber 150, there are formedinlet nozzles 150g and 150h which are adapted to supply fuel to the fuelchamber 150 in opposite directions as shown by arrows 150g' and 150h'towards the igniting means 150f', i.e. in a co-current flow and,respectively, counter-flow relative to the direction of flow ofcompressed air/pressure gas as shown by arrows 150'.

The combustion chamber 150 is shown schematically and by way of examplein FIG. 23, and it may be convenient to make various changes in thepositioning of the fuel nozzles 150g, 150h and, respectively, thepositioning of the igniting means 150f', without necessitating specialexamples thereof. It may for example be convenient to position both (ora different number of) fuel nozzles on one and the same side of theigniting means 150f', for example from opposite sides of the combustionchamber and optionally only in co-current flow relative to the directionof flow of the compressed air supplied to the combustion chamber.

In the embodiment illustrated in FIG. 23, the fuel chamber is shown tobe of more or less constant cross-section in the entire longitudinaldirection, but it may also be convenient to let the cross-sectional areaincrease from one side to the other in the fuel chamber, as indicated inFIG. 24.

It will also be possible to make recesses in the engine housing, suchthat the fuel chamber can be let directly into the engine housing,thereby to make the path of flowing of the pressure medium in the fuelchamber as short as possible.

In the embodiment shown, the volume in the fuel chamber is about 1/12 ofthe volume in each of the four working chambers of the engine, so thatthe compression of the compressed air in the combustion chamber can be1/12 when injecting the compressed air from the working chamber to thecombustion chamber. Other compression ratios can be used to change thevolume in the fuel chamber, as required.

THE PORTS OF THE ENGINE HOUSING

FIGS. 21 and 22 are two opposite end views of the housing 110 of theengine, as seen in the axial direction of the engine, i.e. FIG. 21 is anend view from the side where the half 111 of the engine housing and therotary shaft 117 are seen, while FIG. 22 is an end view from the sidewhere the half 112 of the engine housing and the stator part 116 areseen.

FIG. 22 illustrates a first trapezoidal port 161 which constitutes theintake port from an air inlet 161a on the outside of the engine, asshown in FIG. 11, to the cavity 110b of the engine, and a second,largely rectangular port 162 which constitutes the exhaust port from thecavity 110b of the engine to the inlet side of the combustion chamber150.

FIG. 21 shows a third, largely triangular port 163 which constitutes theintake port from the combustion chamber 150 to the cavity 110b of theengine, and a fourth, largely trapezoidal port 164 which constitutes theexhaust port from the cavity 110b of the engine to an exhaust outlet164a on the outer side of the engine, as shown in FIG. 11.

MODE OF OPERATION OF THE ENGINE

FIG. 24 illustrates schematically at A1-A3, B1-B3, C1-C3, D1-D3, E1-E3five different positions of rotation corresponding to the positions ofthe first and second rotor part of the rotor assembly (position A at 0°,position B at 60°, position C at 90°, position D at 135° and position Eat 180°) in relation to the stator assembly (the guide means 116 and theengine housing 110). The direction of rotation is clockwise in thedepictions A1-E1 and clockwise in the depictions A3-E3. For betterclarity, the stator assembly is not shown, in that it is only indicatedby the combustion chamber 150 and the ports 161-164 which are indicatedby dashed lines. In all the depictions A1-E3, the stator assembly (theengine housing 110 and the guide means 116) is in one and the sameposition, as indicated by the ports 161-164 in the depictions A1, B1,C1, D1, E1 and A3, B3, C3, D3, E3 and, respectively, indicated by thecombustion chamber 150 in the depictions A2, B2, C2, D2, E2. In order todistinguish the parts from each other, the spherical end faces of thefirst rotor part 124 are hatched.

The depictions A1, B1, C1, D1, E1 illustrate the rotor assembly 124, 125as seen in the axial direction form the end where the drive shaft 117 isshown, whereas the depictions A3, B3, C3, D3, E3 are shown in the axialdirection from the opposite end, i.e. from the end where the stator 116is shown. The depictions A2, B2, C2, D2, E3 illustrate the rotorassembly 124, 125 as seen in the lateral direction.

The depictions A1-A3 illustrate the pistons 135, 136 of the rotor part125 in the 0° position of the rotor assembly in one extreme position ofthe pistons, whereas the depictions C1-C3 illustrate the pistons 135,136 in the 90° position of the rotor assembly in the intermediateposition of the pistons, and the depictions E1-E3 illustrate the pistons135, 136 in the 180° position of the rotor assembly (corresponding tothe position in the depictions A1-A3, with the only difference that thepistons 135, 136 have changed positions) in the other extreme positionof the pistons 135, 136.

In continued rotation of the rotor assembly through further 60° (to the240° position) and rotation through further 30° (to the 270° position)and rotation through further 90° (to the 360° position), the pistonstake the corresponding positions as shown in the depictions B1-B3, C1-C3and A1-A3. In other words, for each (360°) rotation of the rotorassembly 124, 125, each of the pistons 135, 136, makes a rockingmovement back and forth (90°+90° rocking movement) between their twoextreme positions as illustrated in the depictions A1-A3 and E1-E3.

It will be understood from the depictions A2-E2 that the workingchamber--positioned on the rear side of the piston 135 on the left-handside of the piston 135 in depiction A2--after the first half revolutionof the rotor assembly (180° rotation, i.e. 90° rocking movement) isexpanded from its minimum to its maximum volume and then is positionedon the left-hand side of the piston 135 in depiction E2 and on thedownwardly facing side of the rotor assembly. In the next halfrevolution of the rotor assembly (180° rotation, i.e. 90° rockingmovement), said working chamber is however rotated, so that it will becorrespondingly shown on the left-hand side of the piston, but then onthe upwardly facing side of the rotor assembly.

Each working chamber will, in turn, perform a corresponding and,respectively, complementary movement. A first pair of working chambers,i.e. the two working chambers arranged each on one side of the piston135, and a second pair of working chambers, i.e. the two workingchambers arranged each on one side of the piston 136, pairwise perform acomplementary movement. The working chamber on one side of the piston135 and the working chamber on the corresponding one side of the piston136 are included in the first two phases of the working cycle, whereascorrespondingly the other two working chambers on the other side of thepistons 135, 136 are included in the two last phases of the workingcycle. In this case, one pair of working chambers cooperate with theports 161, 162, while the other pair of working chambers cooperate withthe other pair of ports 163, 164.

In the 0° position (and the 180° and 360° position), all ports 161-164are closed by the spherical circumferential surfaces of the first rotorpart 124 (the end surfaces shown in A1 and A4).

As shown in the depictions A3-E3, the port 161 for air inlet is whollyor partly uncovered in relation to a first working chamber in the areabetween the extreme positions A3 and E3 (see positions B3, C3, D3), andis only closed in the extreme positions E3 and A3. As appears from thedepictions A3-E3, the port 162 which constitutes the exhaust port to thecombustion chamber 150 is only uncovered by the recesses 162a (162b) ofthe first rotary part 124 in the area between the positions shown in thedepictions D3-E3.

As shown in the depictions A1-E1, the port 164 for the exhaust outlet iscorrespondingly uncovered (open) in the area between the positions shownin the depictions A1 and E1 (see the depictions B1-D1) and is onlycovered (closed) in the extreme positions shown in the depictions A1 andE1. The port 163 is, however, exclusively open in the area between thepositions shown in the depictions A1 and D1 and is closed in thepositions shown in the depictions A1, D1 and E1.

The rocking movement of the pistons 135, 136 makes the pistons sweep theintermediate annular sector of the cavity 110b between the sphericalportions which are swept by the movement of rotation of the pistons 137,138.

The port 162 cooperates with two corresponding recesses 162a and 162b(see also FIG. 16a) in one piston-forming end portion of the first rotorpart. More precisely, the recesses extend partly in the piston surfaceitself and partly in the spherical end surface. The port 162 istherefore guided directly by the circumferential edges of the recesses162a, 162b in the spherical end surface of the first rotor part, i.e.the port 162 is guided by a valve body which is formed of the actualpiston 137 shown at the recesses 162a, 162b. The opening of the otherports 161, 163 and 164 is however guided by the circumferential edge ofthe respective spherical end surface of the first rotor part.

As appears from the depictions A1 and A3, the pistons 137, 138 arelarger in the longitudinal direction than in the transverse direction.This is used to carry out the necessary guiding of the ports 161-164. Inthe depictions A1-A3 and E1-E3, i.e. in the 0°, 180° and 380° positions,all ports are covered by the pistons 137, 138. In the depictions B1-B3,large parts of the ports 161, 163, 164 are, correspondingly, uncoveredtowards the respective three working chambers, whereas in the depictionsC1-C3, the entire ports 161, 163, 164 are uncovered towards therespective three working chambers. In the depictions D1-D3 however, theports 161, 164 are partly covered, while the port 163 (and the port 162)are completely covered by the pistons 137 and 138, respectively. Betweenthe position D1-D3 and the position E1-D3 (45° angle of rotation), theport 162 is, as mentioned above, uncovered.

More precisely, both the intake port 161 and the exhaust port 164 arekept more or less open through a 180° angle of rotation of the rotorassembly (only covered a small angle in the 0°, 180° and 360°positions). The ports 161, 164 are completely closed only in the 0°,180° and 360° positions. This means that an optimal opening time for theports 161, 164 can be obtained, and additionally, optimally largeopenings of the ports 161, 164 are used.

The port 162 from the engine cavity 110b to the combustion chamber 150has, however, a reduced cross-sectional area in relation to the port 161and is kept wholly or partly open through a substantially smaller angleof rotation (45° of 180° angle of rotation) as compared to the port 161.

However, the port 163 is kept open through a slightly larger angle ofrotation (135° of 180° angle of rotation) and has a largercross-sectional area than the port 162. The port 163 opens only afterthe port 162 is closed, and vice versa.

As appears from what has been said above, each working chamber 131-134is in turn and each separately connected to the various ports 161, 162and 163, 164, respectively, i.e. at fixed points of time the fourworking chambers 131-134 each take a different position whichcorresponds to the respective one pair of the four strokes of theengine:

1) suction stroke and 2) compression stroke and, respectively:

3) combustion stroke and 4) exhaust stroke.

By arranging the connecting chamber 150 outside the spherical innercavity of the engine (i.e. radially outside said four working chambers),the respective working chambers are allowed to successively communicatewith the connecting chamber once during each 360° rotation cycle.

From a starting point in the 0° position in which a first compressionchamber has passed the first stroke, i.e. suction stroke 1 (180°rotation in stroke 1 from the 180° position to the 360° position, i.e.in the present case from a point starting from the 0° position), saidfirst compression chamber is subjected to the compression stroke (stroke2) and upon a further 135° rotation to the 135° position, said firstcompression chamber communicates with the connecting chamber 150 throughthe remaining 45° angle of rotation to the 180° position.

In the 180° position, the connecting chamber 150 then communicates,through the following 135° angle of rotation, with a first workingchamber in the expansion stroke (stroke 3) towards the 325° position. Inthe remaining 45° stroke of the expansion stroke towards the 360°position, the connection between the first working chamber and theconnecting chamber 150 is closed. Finally exhaust is discharged throughthe following 180° angle of rotation (stroke 4, i.e. exhaust stroke).

While the first compression chamber and the first expansion chamber aresubjected to strokes 1-4, the second compression chamber and the secondexpansion chamber are subjected to corresponding strokes with an angulardelay of 180° in relation to that above stated.

It is obvious from that mentioned above that the connecting chamber 150through 180° rotation communicates initially with a first compressionchamber and then with a first expansion chamber separately through eachseparate angle of rotation (45° and, respectively, 135°). Through thefollowing 180° angle of rotation, the connecting chamber thencorrespondingly communicates first (45°) with the second compressionchamber and subsequently (135°) with the second expansion chamber.

It is to be noted that the stated angles and angular positions arestated herein as illustrating examples, but that in practice also otherangles and other angular positions may be suitable. A regulation thereofis obtainable by changing the form and location of the ports in relationto the rotor part 124.

By feeding compressed air to the connecting chamber 150 at a compressionratio of say 1/12 simultaneously as fuel is supplied and the mixturethereof is ignited, said connecting chamber is acting as a combustionchamber. As soon as the combustion chamber is closed from thecompression chamber (say in the 180° position), the connection from thecombustion chamber to the expansion chamber is established and thedriving force is transmitted to the expansion chamber through an angleof rotation of 135° towards the 315° position. Through the remaining 45°of the rotation towards the 360° position, the transmission of drivingforce ceases such that the expansion chamber then (in the 360° position)is connected with the exhaust outlet and most of the driving force isutilised in the expansion chamber.

I claim:
 1. A power conversion machine comprisinga housing defining aspherical cavity; a stator secured in said housing on a first axisdisposed radially of said cavity, said stator having an annular groovedisposed in a plane at an inclined angle to said axis; an annular guidemanner slidably mounted in said groove for rotation about a second axisat an inclined angle to said first axis; a shaft rotatably mounted onsaid stator and extending from said cavity; a first rotor part securedto said shaft for rotation therewith, said rotor part having a firstpair of pistons defining ball shaped segments within said cavity of saidhousing for rotation about said first axis; a second rotor part having asecond pair of pistons defining a pair of ball shaped segments withinsaid cavity of said housing, said second rotor part being disposed on asecond axis perpendicular to said first axis with each piston thereofdisposed on an opposite side of said first rotor part to define achamber therebetween; and pin means securing said second rotor part tosaid annular guide member for rocking of said second rotor part aboutsaid second axis during rotation of said first rotor part about saidfirst axis.
 2. A machine as set forth in claim 1 wherein said firstrotor part has a hub portion between said pistons thereof and on saidsecond axis and said second rotor part has a hub portion between saidpistons thereof and on said second axis.
 3. Power conversion machinecomprising a rotor assembly having a first rotor part (124) with a firstpair of pistons (19, 20; 137, 138) and a second rotor part (125) with asecond pair of pistons (33, 34; 135, 136) adapted to be moved in aspherical cavity (10b, 110b) in the machine housing (10, 110), pairwiseand positively in a rocking movement back and forth in relation to saidfirst pair of pistons, said first rotor part (19-21; 124) beingconnected to a driving or driven rotary shaft (17, 117) while saidsecond rotor part (33-35; 125) is non-rotatably connected to said firstrotor part (19-21; 124) so as to perform a conjoint movement of rotationabout the axis of rotation (17a, 117a) of said rotary shaft (17, 117),said first rotor part being rotatable in a first path of revolution in aplane at right angles to said axis of rotation while said second rotorpart is rotatable together with and rockable in relation to said firstrotor part, and said second rotor part being guided by a guide member(38, 119) rotatable in a second path of revolution inclined by means ofstationary guide means (16, 116) at an angle v in relation to said firstpath of revolution, characterised in thatsaid first and said secondrotor part (19-21, 33-35; 124, 125) are defined inwardly of a commonspherical generatrix corresponding to a spherical inner side surface insaid machine housing (10, 110), and that said stationary guide means(16, 116), for guiding said second rotor part (33, 35; 125) in saidrocking movement back and forth, is arranged centrally within the rotorassembly as an elongate stator one end of which is rigidly connected tothe machine housing (10, 110).
 4. The machine as claimed in claim 3,characterised in thatsaid stationary guide means (16, 116) is arrangedcoaxially with said rotary shaft (17, 117) and extends through themachine housing from a bearing connecting with the inner end of saidrotary shaft (17, 117) to a stationary mounting in the opposite end ofsaid machine housing (10, 110).
 5. The machine as claimed in claim 3 or4, characterised in thatsaid stationary guide means (16, 116) consistsof a shaft member which is formed with two stem-shaped end portions(16b, 16c; 116c, 116e) on opposite sides of a substantially ball-shapedintermediate portion (16d, 116g), and that the intermediate portion(16d, 116g) is provided with an annular guiding groove (41, 118) forreceiving said guide member (guide ring 38, 119) which is rotatablymounted in said guiding groove and by means of pins (38, 39; 120a, 120b)and associated bores or like connecting means is connected to the secondrotor part (33-35; 125).
 6. The machine as claimed in any one of claims3 or 4, characterised in thatsaid stationary guide means (16, 116)extends through the center of the first rotor part (19-21; 124), saidfirst rotor part being rotatably mounted in relation to said stationaryguide means (16, 116) at the opposite ends thereof.
 7. The machine asclaimed in any one of claims 3 or 4, characterised in thatsaid firstrotor part (124) is passed endwise through said second rotor part (125)through an annular, radially outer rotor part portion (125a", 135,125b", 136), said first (124) and said second (125) rotor part jointlydefining a lubricant receiving space which is sealed against the workingchambers (131-134) and encloses said stationary guide means (116) andthe associated guide member (119) and the connecting means (121) thereofto the second rotor part (125).
 8. The machine as claimed in any one ofclaims 3 or 4, characterised in thatsaid first rotor part (124) which isin the form of a two-piece hollow body (124a, 124b) forming a casing andprovided with the first pair of exclusively rotating pistons (137, 138),and which is rigidly connected to the rotary shaft (117), is enclosedlocally by said second rotor part (125) which is in the form of twoannular members (125a, 125b) and provided with the second pair ofpistons (135, 136) which both rotate and rock back and forth, and anintermediate transverse connecting means (121) connecting the annularmembers with said stationary guide means (116) via the rotatable guidering (119), and that said two rotor parts (124, 125) jointly define in afluid-tight and preferably also gas-tight manner the working chambers(131-134) of the machine housing from the transverse connecting means(121) and said stationary guide means (116) positioned inwardly thereofand the associated guide ring (119).
 9. The machine as claimed in anyone of claims 3 or 4, characterised in thatsaid first rotor part (124)is defined inwardly of a zone forming an intermediate ball sector in thespherical cavity (110b) of said machine housing, between twopart-spherical portions (125a", 125b") of the annular circumferentialportion of said second rotor part (125), the two opposite,piston-forming portions (135, 136) of said second rotor part (125)forming outer, circumferential connecting means between thepart-spherical portions (125a", 125b") of said second rotor part, in thearea between the axial end portions (137, 138) of said first rotor part(124).
 10. The machine as claimed in claim 9, characterised in thatsaidfirst rotor part (124), in the axial direction in relation to the axisof rotation (117a), has a sleeveforming intermediate portion and twomutually opposite, ball-segment-shaped end portions (137, 138) withcut-off ends, said end portions jointly defining said working chambers(131-134) in the space between the part-spherical ring portions (125a",125b") of said second rotor part (125) and the outer, piston-formingconnecting means (135, 136) which are annularly connected to saidpart-spherical ring portions.
 11. The machine as claimed in any one ofclaim 10, characterised in thatsaid second rotor part (125) is hingedlyconnected to the guide member (119) which is rotatably mounted on saidstationary guide means (116), by means of a central and radially innerconnecting means (121) which is passed transversely through theintermediate portion of said first rotor part (124) in a cavity betweenthe first rotor part (124) and said stationary guide means (116) and theassociated guide member (119).
 12. The machine as claimed in claim 11,characterised in thatsaid machine housing (110) is, at each of itsopposite ends, provided with a pair of ports (161, 164; 162, 163) whichare spaced apart in respect of the angle of rotation, said ports beinglocated inwardly of the paths of movement of the circumferential edgesof the spherical outer surface of the respective one of the end portions(137, 138) of said first rotor part (124) and being adapted to becovered and uncovered by said end portions (137, 138) in the differentpositions of rotation or areas of rotation of said rotor assembly, saidspherical outer surface which is defined on the end portions (137, 138)of said first rotor part (124) and which is symmetrical with the axis ofrotation (117a) of the rotor assembly, having a significantly largerlength than width.
 13. The machine as claimed in claim 12, the machinebeing in the form of a pump, compressor, two-stroke internal combustionengine or like two-stroke engine, characterised in thatthe cavity (110b)of said engine housing (110) defines, by means of the rotor assembly(124, 125), four separate working chambers (131-134) which are eachseparately and in turn pairwise subjected to the two strokes of theengine twice per revolution of the rotary assembly in communication withthe respective pair of the four ports (161, 163; 162, 164) of which afirst port (161) and a third port (163) constitute at the same time theintake port of a first and, respectively, a third working chamber, whilea second port (162) and a fourth port (164) constitute the exhaust portof a third and, respectively, a fourth, working chamber.
 14. The machineas claimed in claim 12, the machine being in the form of a four-strokeinternal combustion engine characterised in thatthe cavity (110b) ofsaid engine housing (110) defines, by means of the rotor assembly (124,125), four separate working chambers (131-134) which each separately andin turn pairwise are subjected to the respective two strokes of the fourstrokes of the engine in communication with the respective port of thetwo pair of ports (161, 64; 162, 163), of which a first port (161) atthe same time constitutes the intake port of a first working chamber,and a second port (162) constitutes the exhaust port for compressed airfrom a second working chamber to a connecting chamber (150) positionedradially outside the working chambers, a third port (163) constitutingthe intake port from the connecting chamber (150) to a third workingchamber forming the expansion chamber, while a fourth port (164)constitutes the exhaust port from a fourth working chamber to theexhaust outlet.
 15. The engine as claimed in claim 14, characterised inthatthe communication chamber (150) which preferably is arranged outsidethe cooling casing (106) of the engine, forms an outer combustionchamber with associated fuel nozzle(s) (150d, 150e) and an ignitingmeans (150f'), the combustion chamber (150) preferably being formed of ahollow body (150a) which is spaced-apart from the engine housing (110)and the cooling casing (106).
 16. The engine as claimed in claim 12,characterised in thatsaid combustion chamber (150) is provided with aninner layer of heat-resistant, ceramic material and preferably a furtherlayer of heat-insulating, ceramic material.